A parameter value used by an operation method. Most CRS parameter values are numeric and can
be obtained by the intValue() or doubleValue() methods. But other types of
parameter values are possible and can be handled by the more generic getValue() and
setValue(Object) methods. The type and constraints on parameter values are given
by the descriptor.

Method Detail

getUnit

Returns the unit of measure of the parameter value.
If the parameter value has no unit (for example because it is a String type),
then this method returns null. Note that "no unit" doesn't means
"dimensionless".
All getter methods which need unit information will invoke this getUnit() method.
Subclasses can override this method if they need to compute the unit dynamically.

valueFile

Returns a reference to a file or a part of a file containing one or more parameter
values. When referencing a part of a file, that file must contain multiple identified
parts, such as an XML encoded document. Furthermore, the referenced file or part of a
file can reference another part of the same or different files, as allowed in XML documents.

getValue

Returns the parameter value as an object. The object type is typically a Double,
Integer, Boolean, String, URI, double[] or
int[]. If no value has been set, then this method returns the
default value (which may be null).
All getter methods will invoke this getValue() method. Subclasses can override
this method if they need to compute the value dynamically.

Returns:

The parameter value as an object, or null if no value has been set and
there is no default value.

setSafeValue

Invoked by all setXXX(…) methods after the argument has been verified to be safe.
Subclasses can override this method if they want to perform more processing on the value
before its storage, or to be notified about value changes.

Parameters:

value - The new parameter value, or null for removing the value currently set.